Apple showed off lots of new goodies at WWDC 2013, including an update to the company’s best-selling MacBook Air line.

The 2013 MacBook Air — available in 11-inch or 13-inch sizes — now comes equipped with Intel’s newest Haswell chipset and promises better battery life with improved graphics performance.

The base model mid-2013 13-inch MacBook Air comes equipped with a 1.3GHz Intel i5 processor (2.6GHz turbo), 4GB of RAM and a 128GB solid-state drive. This model retails for $1,099, down $100 from the base 2012 13-inch MacBook Air.

Customers can further customize the machine to include up to 8GB of RAM, a 256GB or 512GB SSD and bump of the processor from Core i5 to Core i7. As with previous generations, the MacBook Air is not upgradeable after purchase, so if you want to have more RAM or a bigger SSD, you need to make that decision when you buy.

CPU Speed: On Par With 2012

The 2012 MacBook Air has a 1.8GHz Core i5 processor, which clocks higher than the 1.3GHz Core i5 in the 2013 MacBook Air. In theory, you might think that that means the new models are slower than last year. In practice, that’s not really true. While it’s true the processor is clocked lower (in part to help with battery life), the max turbo is the same and CPU benchmarks for the two notebooks are nearly identical.

Running Geekbench 2 benchmarks, the 2012 MacBook Air comes in at 5,812 while the 2013 model reports 6,707. When using CPU-intensive apps, it was nearly impossible to tell a difference.

The CPU is only part of the performance story, however. The real improvements to the 2013 MacBook Air are to battery life, SSD speed and integrated graphics.

Battery Life

The big story with the 2013 MacBook Air is the battery life. Apple promises up to 12 hours (compared with 7 hours on the 2012 13-inch MacBook Pro) and up to 10 hours of movie playback. According to its website, the new battery tests were done at 75% brightness.

Christina Warren from mashable.com tested the video claim head-on and was able to watch two full movies and an episode of Master Chef on Hulu Plus, all on 75% brightness, before the machine shut down. And although she didn’t do a full repeating website test, she did put the MacBook Air through what she considers to be its toughest test — a full workday on her daily driver. With the 2012 MacBook Air, she usually can get 4 to 4.5 hours of battery life under heavy use. That means Safari and Chrome with dozens of tabs each, Photoshop, Dropbox, iTunes or Spotify, a constantly chugging Mail app and any other littany of apps and services.

With the 2013 MacBook Air, she was easily able to go more than 8.5 hours doing the same tasks and with the same apps running. That’s a big deal, effectively doubling the battery life under heavy use.

The battery improvements are largely due to the new features in the Haswell chipset. Teardown reports also suggest the battery itself is slightly larger.

One area Christina Warren did find taxing was on the battery: Flash games. Playing Candy Crush Saga for over an hour was enough to dip the battery more than 20%. Her guess is that if Adobe Flash player was more optimized for the Intel HD 5000 integrated graphics (and had better general OS X support), the battery impact wouldn’t be as severe.

As long as you stay away from Candy Crush, this is the sort of laptop that will easily last all day and then some.

Blazing SSD Speeds

In addition to the new processor, the new MacBook Air also has a new type of SSD. Rather than using a standard SATA connection, the new MacBook Air uses a PCIe connection for the drive.

This is the same type of storage that will be used in the Mac Pro and the results are nothing short of stunning.

Users who opt for a larger SSD may get even faster speeds. Early reports from AnadandTech indicate over 700MB/s read/write speeds on the 256GB variant.

This means that tasks such as copying files to disk and accessing big blocks of data is even faster.

The Best Ultraportable Keeps Getting Better

With the 2013 MacBook Air, Apple has managed to make an already incredible notebook even better. If you’re in the market for an Ultrabook or Ultrabook-like device, the MacBook Air is fantastic across the board.

The machine runs fast, the hard drive is screaming and the battery life actually lives up to its claims. In short, this is an all-around great notebook for anyone who doesn’t need the full power of discrete graphics or the thrill of an ultra-high resolution display.

For new buyers, the 2013 MacBook Air is a no-brainer. If you bought a MacBook Air in the last year, the upgrades (including battery life) probably aren’t significant enough to warrant a new machine. If you’re using a 2010 or 2011 vintage MacBook Pro or MacBook Air, the upgrade is a lot more compelling.